Gilding Metal
Definition
90 percent copper and 10 percent zinc alloy used for bullet jackets in most commercial FMJ and jacketed pistol ammunition; softer than cartridge-case brass and selected to minimise barrel fouling while maintaining jacket integrity.
- Composition
- 90% copper, 10% zinc
- Use
- Bullet jackets in FMJ and jacketed pistol ammunition
- Property
- Softer than cartridge-case brass
- Purpose
- Minimise barrel fouling, maintain jacket integrity
Common questions
Why is a softer alloy chosen for jacket material?+
A softer jacket engages the rifling more easily and deforms slightly to seal the bore, reducing metal fouling buildup compared with a harder alloy, while still holding together well enough to survive firing and impact.
How can gilding metal composition assist bullet-wipe or fragment analysis?+
Jacket fragments or wipe residue with a copper-zinc ratio consistent with gilding metal can help confirm that recovered material is jacket rather than core lead or another metal source.
Is gilding metal used for all ammunition jackets?+
No, other jacket alloys and platings exist, including different copper-zinc ratios, copper-plated steel, and other coatings, chosen based on cost, performance, and the firearm the ammunition is designed for.
Related terms
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- CIP
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- Extruded (Stick) Propellant
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